This invention relates to improvements in a container having a built-in mill wherein, for example, granular coffee beans parched in advance are contained so as to be able to be ground to be powdery when coffee is to be served.
A container having a built-in mill in a container body and capable of being conveyed while containing such grains as coffee beans is already known to have been developed, for example, by the present inventor and disclosed in a Japanese utility model application No. 310,505/1984 (laid open No. 143538/1985).
In the invention of the above mentioned application, as shown in FIG. 6, a cylindrical container body 21 of a container having a built-in mill comprises a can body 22 and a lid 23a sealing the lower part of the can body 22 and a mill 24 is built in the can body 22 so that, after such grains as coffee beans are contained, the upper part of the can boy 22 may be sealed with a lid 23b.
A mill 24 built in the can body 22 comprises a tapered wall 26 held by the inner wall of the can body 22 and a rotor 27 rotatably fitted within this wall 26. A plurality of teeth are provided formed on the inner periphery of the wall 26 and the outer periphery of the rotor 27. Rotor 27 includes a conical surface 28 opposed to the inner periphery of the wall 26 and teeth formed on this conical surface 28.
A gap 29 of an opening area made gradually narrower downward from above is formed between the inner periphery of the above mentioned wall 26 and the outer periphery of the rotor 27 and the upper and lower opening ends of the gap 29 are opened respectively inside and outside the can body 22.
A rotatable rod 31 is connected to the mill 24 through a supporting member 30 in the upper part of the can body 22. A handle 32 is removably connected to the rod 31.
According to this known device, in case the grains 25 are to be made powdery, for example, to brew coffee, when the upper and lower lids 23b and 23a are removed and the handle 32 is inserted in the upper part of the rod 31 and is rotated, the rotor 27 will rotate in the same direction. Therefore, the coffee beans dropping into the gap 29 will be rubbed to be ground by the wall 26 and the teeth provided on the conical surface 28.
However, according to the above-discussed known device, a problem arises in that, when such grains 25A; as coffee beans are light in weight and slippery on the outer surfaces, they will not enter the gap 29 but will be only agitated above the rotor 27 and, in fact, will not be able to be made powdery.
Further, the size of the grains 25 is variously large and small. There is also a disadvantage that, in case the coffee beans are large, when the rotor 27 is merely rotated, the coffee beans will not enter the gap 29 and will not be able to be ground to be powdery.
Therefore, the above mentioned gap 29 can be made large at the upper opening end so that the coffee beans may easily enter the gap 29. However, in such case, in order to make the coffee beans powdery enough, the rotor 27 must be made long and large.
However, when the rotor 27 is made long and large, the content of the coffee beans in the can body 22 will have to be reduced. In order to secure a fixed content of the coffee beans in the can body 22, the container having a built-in mill must be made long and large as a whole and will become inconvenient to convey.